Super glue does not hold at all on shrooms etc....unless it has a bit of substrate on the bottom. But on a bare poly, its not going to hold. Like trying to glue snot.
Best simplest method I have found that works and works well and is easy is to use is with hypodermic needles or dress maker pins. Cut a small piece of rubber band about 1/8/ x 1/8 or 1/4 x 1/4 inches square (like the rubber bands critters are sealed in the bags with) and insert needle or pin through the middle of the rubber piece, insert needle or pin though polyp as close to mouth but not through the mouth, and place polyp on the rock and push / twist pin or needle into the rock. Live rock is relatively soft and easy to get a pin or needle into. Once its pinned in place slide piece of rubber band down to snug polyp against rock , within 5 to 7 days slide rubber band up and see if polyp is adhered to rock, if so pull pin or needle out, if not leave it in for a day or two longer and recheck. Putting a pin or needle through them is not a problem and in no way causes them any harm. They are fragged every day by folks by cutting them up into pieces and they grow back just fine, and a simple pin or needle in them is not gonna even make em notice. Sure beats that netting and wrapping with rubber bands etc . Look for stainless steel dress maker pins if you can not get needles locally. I use insulin needles and they are perfect size.